Tributoxyethyl phosphate is used as a plasticizer and leveling agent in conventional floor coating compositions. However, tributoxyethyl phosphate contains phosphorus; therefore, it is environmentally undesirable because when the tributoxyethyl phosphate is mixed with a floor coating composition, the waste water contains phosphorus. Moreover, organophosphorus compounds, particularly those materials that are used as pesticides, are neurotoxic substances, and today's social climate does not favor the use of organophosphorus compounds. Therefore, there is a demand for phosphorus-free plasticizers and leveling agents as substitutes for tributoxyethyl phosphate.
A polyalkoxylate of a linear aliphatic alcohol is cited in JP (Kokai) 59-206476 as a substitute for tributoxyethyl phosphate as a leveling agent for a floor coating composition. The use of adipic acid esters as leveling agents is cited in JP (Kokai) 6-80933. Coumarin and derivatives thereof are cited as leveling agents in 11-315255. Moreover, improvement of the leveling performance by a combination of a plasticizer with a specific structure and a polyoxyalkylene alkyl ether-type nonionic surfactant is cited in JP (Kokai) 2004-107586.    [Patent Reference 1] JP (Kokai) 59-206476    [Patent Reference 2] JP (Kokai) 6-80933    [Patent Reference 3] (JP (Kokai) 11-315255    [Patent Reference 4] JP (Kokai) 2004-107586